linux-kernel - RE: [PATCH 5/5] x86/unwind/orc: delete dead write in __orc

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Message-ID: <6257b01104da4891af46eec530df1dcb@AcuMS.aculab.com>
Date:   Fri, 11 Mar 2022 15:13:02 +0000
From:   David Laight <David.Laight@...LAB.COM>
To:     'Alexey Dobriyan' <adobriyan@...il.com>,
        "x86@...nel.org" <x86@...nel.org>
CC:     "tglx@...utronix.de" <tglx@...utronix.de>,
        "mingo@...hat.com" <mingo@...hat.com>,
        "bp@...en8.de" <bp@...en8.de>,
        "dave.hansen@...ux.intel.com" <dave.hansen@...ux.intel.com>,
        "hpa@...or.com" <hpa@...or.com>,
        "linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>
Subject: RE: [PATCH 5/5] x86/unwind/orc: delete dead write in __orc_find()

From: Alexey Dobriyan
> Sent: 11 March 2022 14:43
> 
> Also move "mid" variable to the innermost scope and delete useless
> parenthesis while I'm at it.

Hiding the definition of 'mid' in the inner scope is pointless.

I'm also not 100% sure that 'found' is always set.
Consider the ip < orc_ip(first) case.

	David

> 
> Signed-off-by: Alexey Dobriyan (CloudLinux) <adobriyan@...il.com>
> ---
>  arch/x86/kernel/unwind_orc.c | 4 ++--
>  1 file changed, 2 insertions(+), 2 deletions(-)
> 
> diff --git a/arch/x86/kernel/unwind_orc.c b/arch/x86/kernel/unwind_orc.c
> index 2de3c8c5eba9..d38125ea1bf6 100644
> --- a/arch/x86/kernel/unwind_orc.c
> +++ b/arch/x86/kernel/unwind_orc.c
> @@ -35,7 +35,7 @@ static struct orc_entry *__orc_find(int *ip_table, struct orc_entry *u_table,
>  {
>  	int *first = ip_table;
>  	int *last = ip_table + num_entries - 1;
> -	int *mid = first, *found = first;
> +	int *found = first;
> 
>  	if (!num_entries)
>  		return NULL;
> @@ -47,7 +47,7 @@ static struct orc_entry *__orc_find(int *ip_table, struct orc_entry *u_table,
>  	 * ignored when they conflict with a real entry.
>  	 */
>  	while (first <= last) {
> -		mid = first + ((last - first) / 2);
> +		int *mid = first + (last - first) / 2;
> 
>  		if (orc_ip(mid) <= ip) {
>  			found = mid;
> --
> 2.34.1

-
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